1. Technical Field
The present disclosure concerns an energy recovery device enabling energy available in the form of heat to be converted into electrical energy.
It finds a particular but not exclusive application in the field of electronics, enabling energy dissipated by components or electronic circuits to be recovered. In the remainder of the description, it will be described in a more detailed manner for this application, but it can also be associated with various other heat sources (such as for example boilers, industrial equipment, motors, etc.) and can be combined in general terms with any energy recovery device, for example solar, vibratory or thermal energy recovery devices.
2. Description of the Related Art
In general terms, electronic systems, in particular electronic components, give rise to electric currents that by Joule effect cause dissipation of energy in the form of heat.
This dissipation of energy reduces the efficiency of the components and it is desirable to recover all or part of this energy in order to improve the energy balance of a system incorporating electronic components.
Various solutions have already been proposed, which function on different physical principles.
Thus systems have been described using so-called “thermoacoustic” engines, which convert an air flow in contact with the heat source into a standing mechanical wave. This mechanical wave is then applied to a piezoelectric system, which thus delivers energy in electrical form.
Such systems seem difficult to optimize and are apparently not really compatible with use in the microelectronic field, where scale factors impose sizing constraints.
In addition, systems are also known that function on the principle of electromechanical turbines. The heat captured is used to cause a change in phase of a fluid, the gaseous phase of which drives a rotary part, which is itself connected to an electromechanical generator thus delivering energy of the electrical type.
Such systems generally have low efficiency and are the source of wear, due to the fact that the energy recovery is related to the movement of rotary parts, and are especially difficult to miniaturize.
Systems are also known that function using thermoelectrical effects, or Seebeck effect. These devices have the advantage of having no moving mechanical parts. However, in order to obtain satisfactory efficiency, the choice of materials able to generate this thermoelectric effect is relatively small. These materials are generally not very compatible with the constraints imposed in the methods used in microelectronics, for producing components based on semiconductor materials.